Kutschera Ulrich, Niklas Karl J
a Institute of Biology, University of Kassel, Heinrich-Plett-Strasse , Kassel , Germany.
b Plant Biology Section , School of Integrative Plant Science, Cornell University , Ithaca , NY , USA.
Plant Signal Behav. 2017 Jul 3;12(7):e1320631. doi: 10.1080/15592324.2017.1320631. Epub 2017 Jul 10.
Experimental work has shown that Boron (i.e., Boric acid, B) is an essential and multifunctional microelement for vascular plant development. In addition to its other functions, which include xylem development and lignin biosynthesis, we now know that B is involved in phytohormone-signaling and influences the mechanical properties of intercellular pectins. From these data, we conclude that B played an important role during the evolutionary development of lignified tissues, and that it may have been involved in the evolution of vascular plant roots, as hypothesized by D. H. Lewis in 1980. Herein, we review the data pertaining to Lewis' hypothesis, present experimental results on the role of B in root (vs. rhizoid) formation in sunflower vs. a liverwort, and describe the appearance of roots in the fossil record. Open questions are addressed, notably the lack of our knowledge concerning soil microbes and their interactive roles with the micronutrient B during root formation.
实验研究表明，硼（即硼酸，B）是维管植物发育所必需的多功能微量元素。除了其包括木质部发育和木质素生物合成在内的其他功能外，我们现在还知道硼参与植物激素信号传导，并影响细胞间果胶的机械性能。基于这些数据，我们得出结论，硼在木质化组织的进化发育过程中发挥了重要作用，并且正如D. H. 刘易斯在1980年所假设的那样，它可能参与了维管植物根的进化。在此，我们回顾与刘易斯假设相关的数据，展示硼在向日葵与地钱根（与假根相对）形成中作用的实验结果，并描述化石记录中根的出现情况。我们还讨论了一些悬而未决的问题，尤其是我们对土壤微生物及其在根形成过程中与微量营养素硼的相互作用缺乏了解。
